Azalea plant named ‘Conler’

ABSTRACT

A new and distinct variety of Azalea plant found as a seedling in a planned cross between the female Azalea ‘Pink Cheer’ and the male  Rhododendron oldhamii  ‘Fourth of July’. The new variety possesses a unique blooming time and is superior in development of a dense and globose shaped plant with attractive single pink flowers.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct variety of evergreen azalea of the genus Rhododendron and a member of the Ericaceae family. This new azalea variety, hereinafter referred to as ‘Conler’, was discovered by Robert Edward Lee of Transcend Nursery in August, 1986 in Independence, La. ‘Conler’ originated from a planned cross hybridization between two selected breeding lines in a controlled breeding program in Independence, La. The value of this new cultivar lies in its unique blooming period, bloom color, bloom form, and growth habit.

Asexual propagation of the new plant by cuttings has been under Mr. Lee's direction at the same location. The new plant retains its distinctive characteristics and reproduces true to the type in successive generations. The plant cannot be reproduced true from seed.

SUMMARY OF THE INVENTION

The following are the most outstanding and distinguishing characteristics of this new cultivar when grown under normal horticultural practices in Independence, La.

1. The unique spring, summer, and fall blooming.

2. A pink flower color Red Group 51A with dotting color Red Group 53B.

3. Single flowers ranging in size from 1¼″-1¾″ in diameter.

4. Easily propagated with semi-hardwood cuttings in late spring through the summer.

5. Moderate growth rate under normal fertilization and moisture conditions.

6. Dense and globose in nature.

7. Good specimen plant.

8. Desirable in planters.

9. Makes a very good low-growing hedge.

10. Very good foundation plant.

11. Does well as an understory plant in a woodland garden.

12. Hardy to Zone 7.

13. Attracts butterflies.

DESCRIPTION OF THE DRAWINGS

This new Azalea Hybrid variety is illustrated by the accompanying photographic prints in which:

1. FIG. 1 is a close-up showing flower, foliage, and stem color as well as flower size and form.

2. FIG. 2 shows the dense, upright and globose growth habit of a young three gallon plant.

The colors shown are as true as is reasonably possible to obtain by conventional photographic procedures. The colors of the various plant parts are defined with reference to The Royal Horticultural Society Colour Chart. Description of colors in ordinary terms are presented where appropriate for clarity in meaning.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of the new variety of Azalea based on my observations made of 2 year old plants grown in 3 gallon containers in wholesale commercial production practices, in greenhouses, and in established landscape plantings in Independence, La.

Distinctive Characteristics: R. oldhamii Charac- ‘Pink ‘Fourth teristic ‘Conler’ Cheer’ of July’ R. oldhamii Height 3-4′ 2-3′  8-10′  8-10′ (Mature) Width (Mature) 3-4′ 4-5′ 6-7′ 6-7′ Flower 1 1/4-1 3/4″ 3″ 1 3/4-2 1/4″ 1 3/4-2 1/4″ Diameter Flower Form Single Single Single Single Flower Color Red G. 51A Red G. 52A Red G. 39A Red G. 39A Flowers per 3-4 1-4 2-4 2-4 Terminal Bloom Period April Mid-May > Mid-June Bloom Period Mid-July May Early July Sporadic > Frost > Frost > summer Petal Number 5 5 5 5 Hardy Zone 7 7 7 8 Stamen 5-8 10  7-10  7-10 Number

The female, or seed parent, of ‘Conler’ is the Azalea ‘Pink Cheer’; a vivid red, 3″ bloom, early midseason, low, spreading azalea. ‘Pink Cheer’ is an unpatented hybrid developed by Phillip B. Cornell of Fort Bragg, Calif. and released around 1960. ‘Pink Cheer’ is the result of a cross between the light yellowish pink blooming Belgian Indian Hybrid ‘Sweet Sixteen’ (unpatented) and the reddish-orange blooming Rhododendron indicum cultivar ‘Macrantha’ (unpatented).

The male, or pollen, parent is Rhododendron oldhamii ‘Fourth of July’ (unpatented) which originated from a R. oldhamii seed lot collected in 1968 by Dr. Hsu of Taiwan University. The seeds were collected at 850 meters elevation on Mount Tai Tun in Taiwan. Soon after this John Patrick of Oakland, Calif. was visiting Taiwan collecting plant material of the Taiwanese Rhododendrons. He obtained a number of seedlings from Dr. Hsu and grew them in Oakland, Calif. In 1973, Dr. John T. Thornton of Franklinton, La. obtained one of the Rhododendron seedlings from Mr. Patrick Dr. Thornton noticed in the next few years that this particular R. oldhamii plant was a perpetual bloomer from late June until frost on new growth. This plant produces two flushes of growth containing flowers. The second flush of growth overlaps the first flush producing a plant which blooms continuously. This differs from the species R. oldhamii which blooms from mid-May until mid-June and sporadically through the summer. Dr. Thornton subsequently named this plant R. oldhamii ‘Fourth of July’ in 1972.

The azalea ‘Fourth of July’ seems to be hardy to about 10 degrees F. (zone 7). Temperatures below this cause dieback, but the plant readily recovers and blooms profusely the following summer. R. oldhamii is less hardy at zone 8.

Robert Edward Lee's hybridization program was conducted with emphasis on species that are not commonly found in the genetic make-up of the present day hybrids. The ‘Fourth of July’ cultivar which Mr. Lee obtained from Dr. Thornton in 1981 is a heavy summer and fall blooming plant, not like the Rhododendron Species Foundation form. The flower buds form on new growth and start blooming about July 1. Mr. Lee used this cultivar to cross with existing hybrids which have a tendency to bloom in the fall and which are also fairly hardy. As expected the resulting seedlings are heavy summer and fall bloomers with very impressive spring blooms also.

Classification:

Botanic.—Rhododendron hybrid ‘Conler’.

Form.—Dense and rounded.

Height.—3-4′.

Width.—3-4′.

Growth habit.—Dense and globose. Moderate growth rate under normal fertilization and moisture conditions.

Growth rate.—In a period of six years from a rooted cutting the plant reaches a height of 2 feet and a spread of 2 feet. The growth rate is normally about 6 to 8″ per year; the plant reaches a height of 3 to 4′ at maturity while maintaining a dense habit due to the abundant branch development.

Foliage.—Alternate, simple, evergreen, pubescent, elliptic, and varying in size from 1½″ to 1¾″ long and ½″ to ¾″ wide. The margins are entire, with a petiole ⅛″ to {fraction (3/16)}″ long. Midveins and laterals are impressed on the upper leaf surface and prominent on the underside. The base of the leaf is cuneate to attenuate and the apex is acute to mucronate. The upper surface of the immature leaves is dull, pubescent, and is Yellow-Green Group 144A and the underside is Yellow-Green Group 146D, pubescent, and matte. The upper surface of the mature leaves is Yellow-Green Group 147A, dull and slightly pubescent and the underside is Yellow-Green Group 146B, matte, and pubescent. The immature petioles, mid-ribs, and veins are Yellow-Green Group 146C. New growth is pubescent. These hairs are initially soft and white and cover both sides of the leaf with a higher concentration on the petioles and veins. They are slightly curled, flat, and range in length from {fraction (1/64)}″ to {fraction (1/32)}″. As the growth matures much of the leaf pubescence is lost; however, the stems, petioles, and leaf veins retain this pubescence which becomes more setaceous and darker in color (Greyed-Orange Group 167B) through the growing season.

In 1994, the date of initial spring growth was March 10, in Independence, La. After the initial spring flush there was almost continuous growth until that fall ending October 23, also in Independence, La. When grown in full sun, the internode length of this plant is ⅛″ to ⅜″; when grown in light shade the internode length is ¼″ to ½. As would be expected a plant grown in shade results in a taller, less dense plant with larger leaves.

The average length of terminal growth of the initial spring flush is about 4″ for a plant in full sun and about 6″ when grown in shade. This growth should not be trimmed since it will produce flowers starting in mid July. As the plant continues to grow through the summer and fall more flower buds are produced, which mature and bloom until frost. This remaining growth produces about 4″ to 5″ of height. As cool weather approaches, some of the flower buds become dormant. These buds bloom in April of the next year.

Stems: The young stems are Yellow-Green Group 146C and densely clothed with spreading white glandular hairs. During the second growing season they become Greyed-Green Group 197B, glabrous and rugose. The pith is solid and uniform. Young and older stems are densely branched.

Buds: Tight buds at ½″ are ovate and acuminate Yellow-Green Group 146D with a hairy pubescence Greyed-Orange Group 167B. The buds are borne in clusters of 3 to 4, and are sheathed by a pair of modified leaf bracts which are from ¼″ to ½″ long, persistent, and Yellow-Green Group 147A. The pedicel is ¼″ to {fraction (7/16)}″ long, pubescent, and Red Group 53B. The calyx is ⅛″ to {fraction (3/16)}″ long, Yellow-Green Group 144B (both surfaces), funnel shaped, persistent, and pubescent. The five imbricated sepals are lanceolate and joined at the base to form a cup. As the buds swell the bud sheath matures to a Greyed-Orange Group 165A, falls off, and reveals the flower color Red Group 51A.

Flowers: Perfect, single, Red Group 51A (upper surface and undersurface), glabrous, funnel shaped, 1¼″ to 1¾″ in diameter by 1″ to 1¼″ in depth, borne on current season's growth, non-fragrant; they last on the plant in the garden 5 to 6 days. There are five true petals which are elliptic to obovate and fused at the base. These petals are 1″ to 1¼″ long, ½″ to ¾″ wide, and have rounded apexes and entire margins. Three out of five petals are dotted on the upper surface with Red Group 53B. There are 5 to 8 stamens which are ¾″ to 1⅛″ long. The filaments are Red Group 52A, the anthers are Red-Purple Group 59A, and the pollen matures to Yellow Group 11B. The pistil is single, non-petaloid, 1¼″ to 1½″ long and Red Group 53C. The ovary is densely glandular-setose and has five locules. The capsule matures in about 5 months, in Independence, La., to about {fraction (3/16)}″ to {fraction (7/16)}″ long; it has a persistent style, is Yellow-Green Group 147A, and contains from 100 to 400 nonwinged seeds. Normally fruit set is not heavy. There is a 2 to 3 week flowering period in April in Independence, La. Flowering resumes in mid July as the new buds mature and continues until frost which can be as late as November or December in Independence, La. Azaleas blooming at this time of year attract butterflies in profusion.

Culture: Grows well in a wide range of conditions, tolerates sun to shade. Prefers a moist, well-drained soil that is rich in organic matter. Repsonds well to mulching and medium applications of fertilizer; prefers ph 5.0 to 5.5. Very little pruning is needed; adaptable to container and above ground planters; makes a good foundation plant or informal hedge with excellent foliage and flower contrast. Ideal for coastal regions and warmer parts of Piedmont. Propagated with semi-hardwood cuttings in late spring through the summer.

Pests: Lace wing and spider mites can be a problem. 

I claim:
 1. A new and unique variety of Azalea plant named ‘Conler’ as herein shown and described. 